Affected-ear-up 120° maneuver for treatment of lateral semicircular canal benign paroxysmal positional vertigo

Although several researchers have tried various canalith repositioning procedures for lateral canalolithiasis, a standard treatment has not been established. We adopt 120° rotation, which is anatomically appropriate because the principle of cure may be the fixing of pathological debris to the dark cells of the utricle. The aims of this study were to clarify the efficacy rate of the affected-ear-up 120° maneuver and to elucidate the appearance rate of lying-down nystagmus in patients with lateral canalolithiasis. The subjects were 31 patients (26 females, 5 males) who revealed transient direction-changing geotropic positional nystagmus. After determining the involved side, we performed the canalith repositioning procedure immediately. To perform this maneuver: (1) Place the patient in the supine position. (2) Rotate the head toward the healthy side until facing downward 120° from supine. (3) Sit up. (4) Ask the patient to remain upright with the chin down until going to bed. Twenty-nine patients (94%) became symptom free by only one maneuver. However, one patient converted to ipsilateral posterior cupulolithiasis, and another required a second maneuver. Lying-down nystagmus was found in 29 patients (94%), the transient type in 23 (74%), and the persistent type in 6 (19%). The direction of transient (not persistent) lying-down nystagmus was mostly toward the healthy side. These results suggest that the affected-ear-up 120° maneuver is effective and that lying-down nystagmus appears at a high rate.